java.util.Scanner refuses to take the next (or any) input (SOLVED)-CodePudding

"didn't you forget the brackets? .nextLine() .next()" – experiment unit 1998X

"nextLine() is a function when calling function in java we need parenthesis after a function name to invoke a function." – bhawesh agrawal

Current error message "cannot find symbol: variable nextLine in variable input of type Scanner"

Eventually it is going to do much more than this but I don't even understand why it won't read...so it may take a bit XD

Method so far:

public static void flipCoins(Scanner input) 
{
    ArrayList<String> lines = new ArrayList<>();
    while(input.hasNextLine())
    {
        lines.add(input.nextLine);
        // WHERE THE ERROR OCCURS
    }
    System.out.print(lines.toString());
}

These are the links I have been trying to debug with:

whole Scanner class: https://www.tutorialspoint.com/java/util/java_util_scanner.htm

.next() specifically: https://www.tutorialspoint.com/java/util/scanner_next.htm

EDIT FOR MORE

I also receive this error: "cannot find symbol: variable next in variable input of type Scanner", with the following:

lines.add(input.next);

CodePudding user response：

you are missing parenthesis"()", nextLine() is a function when calling function in java we need parenthesis after a function name to invoke a function. similar to what you did here

while(input.hasNextLine())

this will work

public static void flipCoins(Scanner input) 
{
    ArrayList<String> lines = new ArrayList<>();
    while(input.hasNextLine())
    {
        lines.add(input.nextLine());
    }
    System.out.print(lines.toString());
}

CodePudding user response：

You've made this far more complicated than it actually is.

In java, method calls must end in parentheses; they aren't optional. Methods and Fields have separate namespaces - input.next, without the parens, is a field reference (so 'but why won't the language add it!' is a non-starter, it wouldn't be backwards compatible).

Just replace input.next with input.next(), and input.nextLine with input.nextLine().

CodePudding user response：

The call

lines.add(input.nextLine);

Needs ( ) on the end of the .nextLine() because it is a void method within the Scanner class. it could even (but usually shouldn't) be rewritten:

String input = new Scanner(file).nextLine();

Because it is essentially just a piece of the Scanner object.